In the Helicobacter pylori urea breath test, 3 g of reconstituted Pranactin-Citric solution containing 75 mg of (13)C-urea is ingested by the patient. In the presence of urease associated with gastric H pylori, (13)C-urea is decomposed to (13)CO2 and NH(4)(+) according to the following equation:

HPUrease

(NH2)(2) (13)CO + H2O + 2H

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(13)CO2 + 2NH(4)+(13)C-urea

The (13)CO2 is absorbed in the blood, then exhaled in the breath. This results in an increase in the ratio of (13)]CO2 to (12)CO2 in a TEST breath specimen compared to a BASELINE specimen taken before the Pranactin-Citric solution was consumed. Analysis of the breath specimen is performed by infrared spectrophotometry.(Graham DY, Malaty HM, Cole RA, et al: Simplified 13C-urea breath test for detection of Helicobacter pylori infection. Gastroenterology 2001;96:1741-1745)